Aeroplane-landing gear



May 1, 1928. 1,668,122

H. C. MUMMERT ET AL.

AEROPLANE LANDING GEAR Filed May 25. 1926 INVENTOR$ HARVEY C. MUMMERT,

J P F MEADE.

Patented May 1, 1928.

UNITED STATES PATENT OFFICE.

HARVEY C. MUMMERT AND JOSEPH I. MEADE, OF HAMMONDSPOBT, YORK.

Romania-LANDING m Application flied May 25, 1926. Serial No. 111,478.

where snow is likely to be encountered,

has been the practice heretofore'to use in-' terchangeably either wheelsor skis according to ground conditions at the time and place of flight.Such interchangeability .while entirely satisfactory so long as groundconditions remain suitably constant, be

comes increasingly and distinctly otherwise,

under other and (lilferent conditions. If, for instance, a comparativelyheavy snow 18 encountered at the time and place of takeoff and acomparatively light snow, or no snow at all, is encountered at the timeand place of landing..or vice \ersa, neither wheels alone nor'skisalonewill constitute a satisfactory gear." An aeroplane gear, if entirelysatisfactory, should be able to properly and safel function regardlessof the condition of tie ground. Skis should be provided to admit .of aproper landing in the event of snow,'a'nd wheels should be provided toadmitof a proper landing in the absence of snow, the skis and wheelsbeing so relatively arranged and disposed as to in no way interfere onewith the other and if necessary (as for instance under circumstanceswhere it is a moot question which -t.ype gear is best) to cooperate andfunction instantaneously, each in its proper capacity, without attentionand without retracting or extending any part or portion of the gear. Thecombination landing gear of the present invention has been found bactual test to properly fulfill. this long elt want or need.

Other objects of the hereinafter set forth.

. In the drawings, wherein like reference characters denote like orcorresponding parts, f v

. Fig. I is' a side elevation of our improved combination land and snowlanding gear for aircraft;

Fig. 2 is a front elevation, and

invention be landing skis.

In the embodiment of the invention selected for illustration, a landinggear of the type disclosed in the co-pending application of Harvey C.Mummert (one of the joint -onaxle stubs 1111-and two substantiallytriangular frames 12-12 pivoted to the fuselage or body 13 of themachine, the pivot axes in each instange being extended in a fore andaft direction. Said frames 12-12 (see Figf 2) are yieldingly fastenedtogether as at 14 by an appropriate number of shock absorber elastics orcords. Under the impact of landing, said frames 1212 and the wheels10-10 mounted, one at the outer end of each said frame, are movableoutwardly and upwardly against the action of said shock absorbing means.This par ticular type of landing gear, however, is merely illustrativeof the invention and,

if desired, a di'tferent type landing gear may axle stubs 1 111.Preferably the skis 15 are mounted directly upon said axle stubs as bymeans of braces 16 appropriately grouped at opposite sides of the wheels10, each said group being provided at itsuppe'r' end with a suitable hubplate 17 thru which the axle stubs 1111 extend. Beneath said plate 17the skis.15 have formed'therein an elongated slot or opening 18 thruwhich the wheels 1010 project.

At its opposite ends, each ski 15 has fasteued thereto an elastic cord19 by means of which it. is yieldingly. e

Should either' end of eit r ski engage a ground obstruction during use,the cords 19, being elastic, will permit such ground en-v gaging ski endto move upwardl the ski in its entirety pivotingduring sue movementabout the axis stubs 1111 as .centers. A fixed length stop or wire 20 isprovided at the forward end ofeach ski to definitely limit its-pivotalmovement. and at the same time hold it' (the ski) front end foremost,

intothe air stream during fllght.

- It 'will be noted from the above that a combination land and skilanding gear charac- Fi 3 is a perspective view of one of the terized asherein set forth is distinctly advantageousin that a successful take-offandheld in place.

and changes.

stubs obviously both will move-at all times together. 1Neither iscapable, under any circumstances, of yielding vertical movementindependently of the othernotwithstanding 5 the fact that the skis may,undercertain circumstances, pivotallg yield wholly independently of thewhee B extendmgrthe wheels beneath the skis the ending gear, in theabsence .of'snow, ma properly function as anordinary whee ed landingear.

Should snow of any considerable do encountered, the skis would imm'atetli come into use as in lending or ta ofi wi the ground covered byan appreoia le de th the snow crust'liiitil'theskissnp ort the entireweight of the machine. Suc

gear is further wgulvantageogsinth2 1t.the same shock absorber'mans" isused for both so a wheel landin or for a skilanding, or for a landing invw ichhoththe wheels and skis are alternately-used: For "cross-countryfly ing where advance 0 a flightysuoh'a landing gear finds 2'5 itsgreatest use. I Heretofore, whe're skis and wheels have been used incombination, separate shock absorbing means has-been pro vided for eachcharacter of gear. Moreover, if desired, the lending gear can Be maderetractable without-image way de arting from A yi'el'dingly move thespirit of the invehti'ones aimed.

"A Wliilfl have described .mjiffinvention i detail in itsresentpreferredfembodiment, it will be ObVlOtlS to thoseskilled inatheart after understanding my? invention, that various changes andmodifications may be '--made therein without degartmg from the spirit orscope thereof. aim in the appended claims ,to cover all suchmodifications What we claim is:- Y 1. In an aeroplane landing ear,-anaxle,

a ski'hungbelow andicarried 1 said axle,

oundoon'ditions are unknown in said ski having formed therein anopening, a wheel mounted on said axle to lit within said opening, saidwheel andski being incapable of relative movement under impact thocapable of simultaneous vertical movement with said axle, and a shockabsorber for said axle adapted to yieldingly resist the simultaneousvertical movement of both said wheel and ski.

2. A landing gear for aeroplanes including a support structure, wheelscarried by said supportin structure, an axle portion for each wheeincorporatedin said sup porting structure, a ski carried by each saidaxle portiomeach ski havingan openin formed therein thru andbeyondswhich sai a. landing/wheelmproj est-,nndbraces extending betweeneach ski and its associated axle portion, the braces, in each instance,being glrouped on opposite sides of said wheels to ho riorl by andmovable withsaid axle, a wheel carriedb and movable with said axle andextended eneathsaid ski, said wheel having an axis of rotatationwellabove said ski and said axle preventing relative movement between saidwheel andsai'd ski, and a yielding d said skis 'againstbodily yieldingmovement indepe'ncl: r

lo under impaohga ski carv means for resisting the impact movement ofseid axle. v s

In testimony whereof we hereunto allixour signatures.

- VEY C. MUMMERT;

, HAR

' JOSEPH'F. MIEADE.

